NAD is present in essentially every cell of the body except possibly red blood cells.

“yes it's in essentially every cell of the body except red blood cells correct you know I I don't even know if it's in red blood cells my intuition is I I I've never looked to be honest with you but given that red blood cells — have a different metabolic pathway right where they're purely glycolytic I don't they wouldn't have the need for it in the way that others would but they might right because they still undergo Redux potential so it's possible NAD is in every single cell”